1. Field of the Invention
The invention generally relates to a design structure for performance degradation and recovery properties which impact functional systems, and, more particularly, to a design structure of a first system for extending a useful life of second system by optimizing recovery properties associated with devices incorporated into the second system.
2. Description of the Related Art
Negative Bias Temperature Instability (NBTI) is a phenomenon in which powered-up deep submicron complementary metal oxide semiconductor (CMOS) devices exhibit performance degradation over time (i.e., a performance degradation property, an aging mechanism, etc.). For example, NBTI can cause threshold voltage shifts in p-type CMOS devices. Such threshold voltage shifts potentially are a significant impediment to device scaling to smaller geometries because smaller geometries may necessitate smaller threshold voltages. An additional aspect of the NBTI phenomenon is that a powered-down device will conversely exhibit performance recovery over time (i.e., a recovery property). There is a need for circuit and logic designs that are adapted to optimize this recovery property in order to mitigate the effects of aging mechanisms on the usable lifetime and reliability of functional devices and systems in which they are used.